The G31 chipset is Core 2 Duo era, not PentiumD. You have the slowest CPU there is in that series.
Be sure you have the latest BIOS.
Here are the benchmarks for that MB. I'm seeing all CPUs are under 95W.
https://www.userbenchmark.com/System/MSI-G31M3-FMS-7528/42537
The Q6600 scoring 31%CPU is a tapemod to 3GHz.
You could get an E8500/E8600, or if you're looking for adventure an E7500 ($6)with a tapemod to 3.67Ghz will do surprisingly well in single thread games. The 2nd photo is the mod.
https://forums.tomshardware.com/threads/tape-mod-bsel-mod-intel-q6600.1798850/
Here is a benchmark comparing the performance of the tapemod E7500 to a 120W 3.33GHz Xeon X5470.
https://browser.geekbench.com/v4/cpu/compare/14959220?baseline=11904588
DDR2=800 is about equal to DDR3-1066. It's not a deal breaker. I am seeing a 4GB limit which makes things challenging.
With 4GB DDR2-800 I would run a 1GB DDR5 GPU. Don't get a DDR3 card.
The best of these would be a GTX750 1GB DDR5. Probably a low profile version with a tall bracket if needed. The next best would be a GT730 1GB DDR5. The 750 is much better.
The Q6600 G0 will be missing some newer istruction sets. There are only 13 samples of this MB. One of them is a Q8300 quad core. I think it can run a Q9650/9550 series CPU. But I have no confirmed examples of this.
DirectX11 GPU,and SSE4.1 CPU will get you playing some recent games. The 1GB DDR5 will allow decent frame rates but resolution will need to stay well below 1080P. 720P (1280x720) should work well. Old HD720P TVs can get a good sized flat screen for cheap.
Delidded.com shows Xeon swaps for this, but nothing better than the Q9650 they say works on the version listed.
MSI G31M3-L V2 | G31 / ICH7 | 1333 | 95 | Q9650, Q6700, Q6600 (G0 only) | All |
Worked: E5450, E5430, E3113, E5205 | | | | | |